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我一直在使用 cryptography.fernet python 库来尝试加密文件中的某些字符串，但是每次我从文件中读取并尝试解密它时，都会说我将无效令牌传递给了解密函数。我只需要它从文件中读取并将其解密为已读。

我已经检查了我传递给函数的变量类型，它是一个字节类型变量。我已经删除并重新制作了该文件，但我不确定为什么它说它是一个无效的令牌。

file = open(os.path.join("DATA", "pass"), 'r+b')
key = open(os.path.join("DATA", "key"), 'rb').read().rstrip()
crypt = Fernet(key)
read = file.read()
decrypt = self.crypt.decrypt(read)

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3/dist-packages/cryptography/fernet.py", line 85, in decrypt
    raise InvalidToken
cryptography.fernet.InvalidToken

这是我收到的确切错误消息。

我会很感激我能得到的任何帮助。

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1 回答 1

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您需要使用与加密数据相同的密钥在这里您正在生成一个新密钥并尝试使用它来解密您之前使用不同密钥加密的数据。在下面的代码示例中。你可以看到我已经生成了 2 个密钥。我用第一个密钥加密数据，我可以用第一个密钥成功解密它。但是，如果我尝试使用第二个密钥解密，则会收到无效令牌错误，因为这不是我用来加密数据的密钥

from cryptography.fernet import Fernet


def my_encrypt(key, data):
    f = Fernet(key)
    return f.encrypt(data)


def my_decrypt(key, data):
    f = Fernet(key)
    return f.decrypt(data)


my_key = Fernet.generate_key()
other_key = Fernet.generate_key()
my_string = b"my deep dark secret"
print(my_string)
my_encrypt_string = my_encrypt(my_key, my_string)
print(my_encrypt_string)
my_decrypt_string = my_decrypt(my_key, my_encrypt_string)
print(my_decrypt_string)
other_decrypt_string = my_decrypt(other_key, my_encrypt_string)

输出

b'my deep dark secret'
b'gAAAAABdSoKHUm4xCGDZ1JYneogK62U_GQnluw-ekn8xRi0rT8_9FzK0iMY41pksCg5OpPgoD0pJlJFsGF4WjIMeMWVpPdkQklL2JjQbbEhfcx6Qpazm_eA='
b'my deep dark secret'


Traceback (most recent call last):
  File "C:\Users\cd00119621\AppData\Local\Programs\Python\Python37\lib\site-packages\cryptography\fernet.py", line 106, in _verify_signature
    h.verify(data[-32:])
  File "C:\Users\cd00119621\AppData\Local\Programs\Python\Python37\lib\site-packages\cryptography\hazmat\primitives\hmac.py", line 69, in verify
    ctx.verify(signature)
  File "C:\Users\cd00119621\AppData\Local\Programs\Python\Python37\lib\site-packages\cryptography\hazmat\backends\openssl\hmac.py", line 73, in verify
    raise InvalidSignature("Signature did not match digest.")
cryptography.exceptions.InvalidSignature: Signature did not match digest.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:/Users/cd00119621/PycharmProjects/ideas/stackoverflow.py", line 22, in <module>
    other_decrypt_string = my_decrypt(other_key, my_encrypt_string)
  File "C:/Users/cd00119621/PycharmProjects/ideas/stackoverflow.py", line 11, in my_decrypt
    return f.decrypt(data)
  File "C:\Users\cd00119621\AppData\Local\Programs\Python\Python37\lib\site-packages\cryptography\fernet.py", line 75, in decrypt
    return self._decrypt_data(data, timestamp, ttl)
  File "C:\Users\cd00119621\AppData\Local\Programs\Python\Python37\lib\site-packages\cryptography\fernet.py", line 119, in _decrypt_data
    self._verify_signature(data)
  File "C:\Users\cd00119621\AppData\Local\Programs\Python\Python37\lib\site-packages\cryptography\fernet.py", line 108, in _verify_signature
    raise InvalidToken
cryptography.fernet.InvalidToken

因此，当您加密数据时，您需要存储用于加密它的密钥，因为您将需要使用相同的密钥来解密它

于 2019-08-07T07:54:00.870 回答